Teenager Michael Piggin, who kept a stash of weapons in his home but denied he was planning a repeat of the Columbine school massacre, has been detained under the Mental Health Act.

Piggin (18) admitted possessing petrol bombs and component parts of pipe-bombs for use as explosive devices.

He also pleaded guilty to possessing the component parts for improvised explosive devices.

Police discovered a hoard of petrol bombs and air rifles when they were called to investigate a public order offence from six days earlier at his home in Beaumont Road, Loughborough, in February last year.

Piggin, who has Asperger's syndrome, denied he was going to attack his old school.

In sentencing at the Old Bailey, Recorder of London Brian Barker QC told Piggin that he should be held "under the Mental Health Act, which will provide you with appropriate treatment for as long as is deemed necessary".

The judge said: "This is not a case of a determinate sentence. It is clear that you need treatment."